Effeet of Saturation of Magnetic Leakage Path on the Circle Diagram of the Three Phase Induction Motor

Abstract

It is well known fact and discussed by many authorities, that the satu-ration of the magnetic leakage path will affect upon the circle diagram of the three phase induction motor. Mr. B.A. Behrend (1) has shown that the circle diagram of the induction motor, which has closed slots, will be greatly deformed from the circle, and recently Mr.H.K. Whitehorn (2) has published very interesting paper which tell us the centre of the circle will be lowered owing to the saturation of the magnetic leakage path of the closed slots. These imestigations, however, tell us only the results of experiments and give no idea to correct the circle diagiam for this effect. The author explain here a new idea of the correction of the circle diagram for the effect of saturation.
The author's principle for the circle diagram is due to that "A circle of current locus, which is constructed from the test results of no load and of short circuit, is only true at a current by which the locked (or short circuit) test is carried out." Because the degree of saturation at the current, bywhich the motor is locked, is practically equal to the degree of saturation of the working condition of the same current.